Optimizing solution-processed nanosheet networks
for electronic applications requires understanding the
relationship between nanosheet dimensions, network morphology,
and electrical properties. Here, we fabricate graphene
nanosheets with both low- and high-aspect-ratios using liquidphase
exfoliation (LPE) and electrochemical exfoliation (EE),
respectively. Spray-coated networks of both nanosheet types
display distinct morphological and electrical properties. Highresolution
3D imaging shows that low-aspect-ratio LPE nanosheet
networks display a disordered, porous structure with
point-like junctions. Conversely, high-aspect-ratio EE graphene
forms low-porosity networks with highly aligned nanosheets
with large-area conformal junctions. Electrical measurements demonstrate that EE networks achieve lower resistivity and
reduced percolation thicknesses due to reduced junction resistances and improved nanosheet alignment. We propose a
theoretical model linking nanosheet bending rigidity, aspect ratio, and junction formation, highlighting the critical role of
nanosheet flexibility in enabling conformal junctions. Furthermore, by size-selecting both nanosheet types, we measure the
dependence of network resistivity on nanosheet thickness. LPE networks show increasing resistivity with thickness, whereas
EE networks exhibit decreasing resistivity. We develop a simple model linking these behaviors to point-like and planar
junctions respectively and quantify the size-dependence of both nanosheet and junction resistance for both cases.
Unexpectedly, data analysis using this model predicts the EE nanosheets to be more conductive than the LPE ones, a fact
confirmed by THz spectroscopy. This study establishes the importance of nanosheet aspect ratio and flexibility in governing
network morphology and electrical performance. Our findings provide key insights for developing high-performance, solutionprocessed
2D material networks for future electronic devices.
«
Optimizing solution-processed nanosheet networks
for electronic applications requires understanding the
relationship between nanosheet dimensions, network morphology,
and electrical properties. Here, we fabricate graphene
nanosheets with both low- and high-aspect-ratios using liquidphase
exfoliation (LPE) and electrochemical exfoliation (EE),
respectively. Spray-coated networks of both nanosheet types
display distinct morphological and electrical properties. Highresolution
3D imaging sho...
»